In Any Text Editor

Countless productivity apps and sites store your tasks in their own proprietary database and file format. But you can work with your todo.txt file in every text editor ever made, regardless of operating system or vendor.

The todo.txt format is a simple set of rules that make todo.txt both human and machine-readable. The format supports priorities, creation and completion dates, projects and contexts. That's all you need to be productive. See an example Todo.txt file.